Final Cut Pro XML to Shake is a small application that takes an exported Final Cut Pro XML export into a format that Shake can import and use as the basis for a Shake composition. This is effectively the same type of integration that is built-in with Motion.
The Shake script output has nodes grouped by reel and sorted in shot order, with a cut list showing clip in and out points. The final version will allow high resolution frame sequences to be swapped for the exported media, but that does not function in this release.
The script is beta and the author is looking for test Sequences to test more complex case studies.